SCIENCE

August 15, 2005

Bear Study Reveals Heavy Contamination of Salmon

Canadian grizzly bears that gorge on spawning Pacific salmon have much higher contaminant levels in their bodies than those that consume mostly berries, plants and insects, according to research to be published Sept. 15 in the American Chemical Society journal, Environmental Science and Technology.

Peter Ross, a scientist at Canada's Institute of Ocean Sciences, used fat and hair samples culled from 12 legally hunted bears in British Columbia to ascertain whether they absorbed persistent organic pollutants, or POPs. The results were "profound," Ross wrote.

Ross said Thursday in an interview that the two groups of bears "had completely different profiles, in terms of their contaminants." Salmon-eating bears accounted for 90 percent of the PCBs researchers found, 70 percent of the pesticides and 85 percent of the less-brominated flame retardants.

He also noted that much of the pollution originated in Asia. "We've got a reminder here about how small the planet is," Ross said.

The fact that grizzlies that consume marine foods as well as terrestrial foods accumulate more contaminants, he added, raises a concern because scientists have already documented how persistent organic pollutants "can present, and have presented, health risks to wildlife species at the top of the food web."

-- Juliet Eilperin

Compound Added to Spin Cycle Makes Clothes Less Wet

Scientists are putting a new spin on laundry detergent.

University of Florida researchers say that their compound, added before the spin cycle, loosens the force between water molecules and helps fabrics shed as much as 20 percent more water, thus shortening the time needed to dry the clothes.

"A 10 percent reduction in the drying time could save the country up to $250 million per year," said Dinesh Shah, a professor of chemical engineering at the university, whose research was funded by a $200,000 grant from soapmaker Procter & Gamble.

Although a product is three to five years from appearing on store shelves, "the fundamental aspects are pretty much resolved," said Shah, whose research is being published this month in Langmuir, a journal of surface chemistry.

"It's like a chef who wants to make a [different] cookie," Shah said. The same ingredients, such as sugar and water, are used but in different proportions, he explained, alluding to the mixture of detergents and fabric softeners.

The method of delivery still needs to be fine-tuned. A capsule that would break open before the spin cycle, or a spray, are two possibilities, Shah said.

Daniel Carter, a doctoral student at Shah's lab and the lead researcher of this study, noted that 56 percent of Americans own electric dryers, typically handling 300 loads a year. Based on his calculations, drying clothes can account for 5 percent of total household electricity consumption.

"So the ultimate goal is to save energy and save time," Shah said.

-- Naseem Sowti

Shuttle Brings Local Students' Experiments Home From Space

Returning with the space shuttle Discovery last week were 20 tiny vials containing experiments that had been sent by U.S. students to the international space station last year.

"These are passive experiments, which allow the students to compare the results to the equal experiments performed here," said Chuck Brodell of the Educational Flight Projects Office at Wallops Flight Facility on Virginia's Eastern Shore.

Students at Shady Side Elementary in West River, Md., for example, sent long-lasting light bulbs to find out whether they would be more effective for space use.

The Walkersville Christian Family School in Stockton, Md., sent selected seeds and egg cysts from organisms that fish eat to examine the effects of microgravity and radiation.

Wallops Flight Facility has been making the collaboration between the schools and NASA possible since 1996.

"We're all about getting students excited about math, engineering and science," Brodell said. He added that students are the scientists for these experiments, and "they designed and developed these projects, and they're doing the investigation."

Brodell speculated that the experiments are still in California and will make their way back to the schools by September.

-- Naseem Sowti

A study of Canadian grizzlies found that they ingested high levels of pollutants from salmon.